Wing retraction type mis-piercing preventer and winged needle having the mis-piercing preventer

ABSTRACT

A winged needle cover capable of storing an entire needle with flexible wing in the state of the needle tube part of the winged needle not projected again, comprising a tip side opening part for taking therein the entire winged needle having a flexible tube connected thereto and a base side opening part allowing the flexible tube to pass therethrough, characterized in that, a wing part folding promoting means capable of upwardly reversing the wing part of the winged needle for folding when the entire winged needle is taken from the tip side opening part into the needle cover is provided at the tip side opening part, whereby, the needle cover can easily store the winged needle after servicing, makes it hard for the stored needle to be re-projected and, because any special means is not provided for prevention of re-projection, can be manufactured easily at a low cost.

TECHNICAL FIELD

The present invention relates to a needle cover for actively preventingpollution and/or infection or other accidents caused by inadvertentpuncture with an injection needle/puncture needle, wherein a wingedneedle as a whole can be retracted after its use into the needle cover(wing-retraction type inadvertent puncture protector), and the retractedwinged needle can be retained with its needle tip being prevented fromre-protruding from the needle cover, said needle cover requiring no slitto be aligned with the wing of the winged needle while retaining theneedle, and the invention also relates to a winged needle comprising atleast said needle cover (inadvertent puncture protector).

In medical facilities, pollution and/or infection due to inadvertentpuncture with an injection needle/puncture needle has become a seriousissue. Recently, to actively prevent accidents such as inadvertentpuncture, a piece of legislation to enforce the use of inadvertentpuncture protectors has been enacted in each state of the United States.Also, although no legislation has been enacted as in the Untied States,in many other countries including Japan and Europe, methods and/or meansfor preventing inadvertent puncture have attracted much attention ofmedical professionals.

The above described inadvertent puncture protectors herein refer not tosimple, inexpensive conventional needle covers, but to ones with whichthe needle can be covered requiring no operation which may causeinadvertent puncture during the retention of the needle after its use,or ones with which the needle can be covered by an operation which isless likely to cause inadvertent puncture. Accordingly, even if they caneffectively prevent inadvertent puncture, such devices would not bereadily utilized in every medical facility and its branch. Moreover,adoption of such inadvertent puncture protectors would cause increasesin cost as well as operators' work time. From these reasons, the abovedescribed means and/or methods for preventing inadvertent puncture havenot prevailed as desired throughout current medical facilities for whichreduction of medical expenses and simplification of operating processesare demanded.

As the injection needle and/or indwelling needle, a needle which isformed with a wing at its hub (needle base) are widely used tofacilitate its grasping and indwelling. However, since the wing hindersthe retention of the needle after use, the needle cover for retainingsuch winged needles tends to make the size of the needle larger as awhole compared with one for wingless needles. Therefore, somecontrivance is needed to make the needle cover compact.

One simplest solution to solve the above-described problem is aninadvertent puncture protector in which a slit is provided in the needlecover; various such devices have been proposed. For example, JP, B,06-7861, JP,A,08-206195, JP,B,04-36026, and others exemplify such thosedevices. However, since the above described needle covers must have thewing inserted along the slit, alignment was needed when retaining thewing, thereby making the operation cumbersome. Also it was necessary tocarefully design the position, angle, and width of the slit of theneedle cover such that the wing is readily inserted into the slit.Furthermore, the above-described slit must have a shape, size andstructure to facilitate the sliding of the wing because the wingedneedle must be easily moved in the needle cover.

On the other hand, contrasting to the above described prior arts, meansfor retaining a puncture needle in a needle cover with no slit have alsobeen proposed. One example is the needle cover disclosed in U.S. Pat.No. 5,030,212. The needle cover has a front end having an opening of ahorn shape, through which the wing (mounted on the hub) is folded to beretained in the needle cover after use. This needle cover has no slit,and therefore there is no need to pay attention to the above describedrequirements concerning the slit, such as alignment, shape and size ofthe needle cover, thereby making the production and/or formation thereofeasy.

However, the inadvertent puncture protection means exemplified by theabove mentioned patent (U.S. Pat. No. 5,030,212) had a problem, as willbe described below, concerning the retainability of winged needle andre-protrusion of the retained needle. First, regarding the retainabilityof winged needle, since the front end opening of the needle cover isshaped like a horn (radially expanded front end), it is easy to retainthe winged needle into the needle cover in the beginning, but themobility of the winged needle in the needle cover becomes extremelydegraded at the transition portion to a cylindrical part with a smallerdiameter. Also, if the inner diameter of the cylindrical part isincreased excessively to improve the mobility, the needle cover willbecome too large and holding the winged needle retracted into the needlecover in position becomes difficult.

Needle covers with no slit had a common problem described below, thoughthat is not specific disadvantage to the horn-type needle coverdescribed above. That is, the mobility of the needle in a needle coverdepends on wing-folding (retaining) state. For example, when the wingedneedle is inserted, in the beginning, into the needle cover with itspart being trapped or twisted, the winged needle becomes extremelydifficult to move. Otherwise, the retention of the needle itself becomesdifficult. Thus, the mobility and/or the retainability of winged needlein a needle cover are affected by wing-folding state (in the needlecover). Therefore, it was difficult to secure a certain level ofmobility and the retainability for a needle cover which places norestriction on the wing-folding state. Upon retracting a winged needleinto a needle cover, keeping the wing at the position of a radiallyexpanded part (with a horn like taper), the needle tip tends to move inthe reverse direction (against the retraction direction) due to thetaper and the restoring force of the folded wing. That is, there is arisk of re-protrusion of the retained needle. In the needle coverdisclosed in U.S. Pat. No. 5,030,212, an open hole for engaging the wingis provided in the base end of the needle cover to prevent there-protrusion of the needle. However, this engaging means of the wingedneedle not only caused increases in workload in the production processand in cost, but also had a problem in that the folded wing does notreadily protrude from the opening hole at the needle retaining positionand thus does not function well as the engaging means.

DISCLOSURE OF THE INVENTION

The first of the present invention is a needle cover comprising a frontend opening through which a winged needle as a whole is retracted and abase end opening through which a flexible tube connected to the wingedneedle is passable, the needle cover being capable of retaining thewinged needle as a whole with the needle tube of the winged needle beingprevented from re-protruding, characterized by comprising wing-foldingfacilitating means which is formed in the front end opening and can foldthe wing of the winged needle by gradually turning it upwardly when thewinged needle as a whole is retracted into said needle cover throughsaid front end opening.

The second of the present invention is a winged needle having awing-retraction type inadvertent puncture protector, characterized byconsisting of at least a winged needle, a flexible tube connected tosaid winged needle, and the above described needle cover being looselyfitted to said flexible tube.

The components of the needle cover of the present invention, and theconfiguration of a winged needle mounted with said needle cover will bedescribed below specifically referring to each component.

Needle Cover

A needle cover of the present invention has a front end opening throughwhich a winged needle as a whole is retracted and a base end openingthrough which a flexible tube connected to said winged needle ispassable, and the needle cover is capable of retaining the winged needleas a whole with the needle tube of the winged needle being preventedfrom re-protruding. The needle cover has a configuration, for example,consisting of a substantially flat bottom face, both side facesconnected to said bottom face and a top face connected to said both sidefaces.

The size of the small-diameter opening of the base end side of theneedle cover may be such that the flexible tube connected to the wingedneedle can pass through it, but it is preferable to make the size of thesmall-diameter opening about the same as the outer diameter of saidflexible tube so that the winged needle will not accidentally move inthe retraction direction, or slightly smaller than the outer diameter ofthe flexible tube so that, when the outer force applied on said flexibletube is released, the flexible tube is lightly supported by thesmall-diameter opening while the passage of the flexible tube is nothindered.

The needle cover of the present invention comprises a wing-foldingfacilitating means capable of folding the wing by turning it upward asdescribed below, and more preferably comprises at least one ofwing-retention support means as will be described below,slide-resistance reducing means for the wing, and wing-directionrestricting means.

There is no limitation on the material for said needle cover providedthat the material has enough rigidity to support the deformation of thewing of the winged needle. However, as the material of the needle cover,a transparent to semi-transparent material is preferable since theretraction position of the winged needle and the retaining condition ofthe wing can be confirmed. Examples include polyolefins such aspolyethylene and polypropylene, polystyrene, acrylic resin, polyesterresin, and the like.

Wing-Folding Facilitating Means

The wing-folding facilitating means refers to means for facilitatingwing-folding by turning the wing of the winged needle upward whenretracting the wing of the winged needle into the needle cover throughthe front end opening; examples of which include means in which thefront end opening is configured to be an inclined open face.

Examples of the front end inclined open face adopted as saidwing-folding facilitating means include one in which an inclined openface is formed with respect to the needle cover bottom face from thefront end side upwardly toward the base end side of the needle cover asshown in FIGS. 1, 2, 3, 4, 5, 8, 9, 10 and 11.

When the wing of a winged needle is rolled up by said inclined face andfurther pushed into the internal space of the needle cover from saidfront end opening toward the base end in a state that the side face orthe base face of the wing, which has been rounded up smoothly, is inabutment with the end edge of the front end side opening of the needlecover, the end side bottom face of the wing comes into abutment with theinternal space side of the bottom face of the needle cover, and thewinged needle is readily retained into the needle cover in a state thatthe wing is turned around or turned around and twisted while the endside bottom face of the wing being abutting against the internal spaceside of both side faces or the internal space side of the top face ofthe needle cover. The wing which thus has been readily rolled up is veryeasy to be retained in the needle cover.

Further, at this moment, since the turned wing end is folded in thedirection nearly opposite to the retraction direction (base end side),the winged needle is easier to be moved in the retraction direction(forward direction), and difficult to be moved in the re-protrudingdirection (reverse direction) since the wing end acts as a trap.Therefore, there is no need for providing special re-protrusionprevention means on the needle cover. Also, for the movement in theforward direction, the winged needle can hold its retaining position inthe cover preventing its free movement while no external force isapplied, since the wing abuts against the internal space wall of theneedle cover.

In the needle cover of the present invention, the relation between thearea S of the wing specified by the width and length of the wing, andthe inner perimeter L at the front end opening of the needle cover isalso important. When the wing area S is excessively larger than theinner perimeter L, the wing will fill the needle cover to the full thusmaking the retention of the winged needle difficult. On the contrary,when the inner perimeter L is too large with respect to the wing area 5,it will hinder the operation and, therefore, become a waste.

Particularly, provided that the inner perimeter of the inclined openingof said needle cover be L (FIG. 6), and the distance between both endsof the wing of the winged needle retained in said needle cover be d1(FIG. 7), when a needle cover is configured such that L/3 ≦d1 ≦L, it iseasy to retract the wing 6 into the cover 1 and furthermore it ispossible to achieve a compact, and no-slit needle cover. When the innerperimeter L is as small as it does not satisfy the above-describedrequirement, the oversized wing is shrunk thereby hindering theretraction (insertion) of the winged needle into the cover and thesliding movement therein. On the contrary, when the inner perimeter L isas large as it does not satisfy said requirement, the needle coverbecomes too large thereby degrading the usability.

After all, said L may be 3 to 9 cm, preferably 4 to 8 cm, and morepreferably about 5 to 7 cm.

Wing-Retention Support Means

Since the folding condition of the winged needle in the needle coveraccording to the invention is determined at the moment when the wing isinserted, it is possible to stabilize and uniform the retaining(folding) condition of the wing of the winged needle in a needle coverby providing wing-retention support means particularly in the front endopening.

Said wing-retention support means may be configured such that the sideface and/or top face of at least the front end opening has a convexshape protruding in the outward direction, that is the oppositedirection to the inside of the internal space of the needle cover.Examples of such configuration include one in which both side faces 4 a,4 b of the needle cover bulge forming a convex shape outwardly in theaxial direction (opposite side of the inside of the internal space) ofthe needle cover including the front end opening (as with FIGS. 8, 9 and10).

When both side faces 4 a, 4 b of at least front end face of the needlecover bulge outwardly in a convex shape as described above, the wing ismore readily rolled up when retracting the wing of the winged needleinto the front end opening. Further, the wing is placed along thebulging part 12 which is of a outwardly convex shape and the wing tippart is folded in the predetermined direction, allowing the wing to bemore smoothly folded and thereby more readily inserted into the needlecover rather than a case in which both side faces 4 a, 4 b of the needlecover are vertical. Thus, it is possible to make the retention (folding)condition of the wing of the winged needle in the needle cover morestable and uniform.

Furthermore, the needle cover thus formed with a bulging part showsbetter reproducibility of the retaining condition when further repeatingthe retaining operation. And unless there is no significant deviationduring retraction, substantially same retaining condition will beinduced. On the contrary, when the wing is trapped in the needle cover,or the wing or the hub is rotated by 90 to 180 degrees, there ariseslarge resistance when retracting the winged needle into the cover, thusallowing to prevent retraction of the wing in an improper condition.

Furthermore, when said bulging part formed at the front end opening isformed in the axial direction in the both side faces of the needlecover, it will provide significant effect not only on the retainabilityof the wing but also on the mobility thereof.

Though the above described bulging part may be formed through the entireregion in the axial direction of both side faces of the needle cover asdescribed above, it will be sufficient to form it in the range from thefront end opening, which relates to the folding of the wing uponstarting the wing retention, to the portion of both side faces againstwhich the wing abuts when it is completely covered with the needlecover.

A preferable position in the both side faces in the vertical directionfor forming the bulging part is to be decided by the position where thewing of the winged needle is formed, but generally about the middle partbetween the bottom face and the top face of the needle cover would bepreferable since this would give a larger tolerance for producing thewing-retention effect when retaining the winged needle into the needlecover.

Further, the shape of the bulging part may be either one having anangular apex 12 bulging toward outwardly (lateral direction with respectto the axial direction) as shown in FIG. 5, or one having a curved apex(or bulging part) bulging outwardly (lateral direction with respect toaxial direction) (not shown). Either in the case of an angular bulgingpart or of a curved bulging part, the angle of the apex is preferablywithin the range of 110 to 170 degrees. Either excessively small orexcessively large apex angle will make it difficult to assure space forrolling up the wing and releasing it laterally and, therefore, thenatural rolling up effect of the wing will degrade, thereby making theretention of the wing difficult.

A wing-retention support means having a shape of the above-describedbulging part may be formed on the top face of the needle cover, althoughthat will have less effect than the case in which the bulging part isformed in the side faces of the needle cover. In this case, it ispreferable to form a bulging part in the top face in addition to thebulging part formed in the side face of the needle cover. This bulgingpart formed on the top face of the needle cover also preferably has ashape which is formed by bulging the top face of the needle coveroutwardly (upwardly). And its shape may be either one having an angularapex bulging outwardly (upwardly), or one having a curved apex (orbulging part) bulging outwardly (laterally) as with the bulging partsformed on the side faces. And, upon forming a bulging part on the topface of the needle cover, when an outwardly (upwardly) bulging shape isformed as shown for example in FIG. 5, the apex of the bulging part mayform a flat part since wing-direction restring means is provided bymeans of a stripe rib 14.

Moreover, this angular or curved bulging part on the top face needs notto be formed along the entire length of the axis of the needle cover,and it will be sufficient to form it in the range from the front endopening, which relates to the wing folding upon starting the wingretention, to the portion of both side faces against which the wingabuts when it is completely covered with the needle cover.

Wing Slide-Resistance Reducing Means

As other wing-retention support means, following slide-resistancereducing means may be adopted. That is, at least a part of the edge ofthe front end opening which may abut against the wing when retaining thewinged needle into the needle cover is rounded to reduce theslide-resistance or, an emboss finishing may be applied to form tinyirregularities on at least a part of the portion which may abut againstthe wing inside the internal space of the needle cover to reduce theslide-resistance.

Wing-Direction Restricting Means

Further, as another wing-retention support means, it is desirable toprovide direction restricting means which is capable of preventingimproper retention of the winged needle into the needle cover andrestricting the advancement and retreat of the needle in the covergenerally to the predetermined direction.

One example of said direction restricting means is configured such thata straightline stripe projection 14 is formed in a proper portion in theinner surface of the internal space of the needle cover as shown inFIGS. 2 and 5, and the wing tip part is moved along said projection.

Furthermore, since, in most cases in which the wing has been retainedinto the cover, the wing end is placed on the internal space side of thetop face of the needle cover, the portion in which the above describedstripe projection 14 is formed preferably in the internal space of thetop face, and particularly the middle part of the internal space of thetop face is more preferable since intended direction restriction effectmay be produced most effectively.

In the case of the winged needle equipped with said wing-directionrestricting means, the wing tip is moved while abutting against saidstripe projection 14 thereby being geometrically restricted. Thereforethe wing will show a linear track along the stripe projection, andtherefore when the winged needle is retained as being inclined againstthe cover, or when the bottom face or the cover is not parallel with theflat part of the wing, and if there is no large deviation, the positionof the wing end is restricted by the stripe projection 14, and thus theretention condition may be readily adjusted.

Holding (Pressing) Member

Providing an arcuate projection 21 on the top face near the base endopening as shown in FIGS. 1, 2, 3, 4, 8, 9 and 13 for the purpose ofholding (pressing) makes it possible to pull the tube backward (base endside) while pressing the top face of the needle cover after the use ofthe needle. Thereby, the winged needle can be easily retained into thecover.

In the winged needle having inadvertent puncture prevention deviceaccording to the present invention, its characteristic features residesmostly in the needle cover side. However, the wing of the winged needlemay have a specific structure or configuration so that the winged needlecan be readily retained into the needle cover.

Such examples include a wing which has a hardness of 10 to 100 asspecified by JIS-A, or a wing having a structure which has a tendency ofbending upward by means of said wing-orienting means of the needlecover. Examples of the wing having such structure include one having astructure which will readily become prone to bend upward, or one havinga structure which has acquired such feature in advance.

Furthermore, for the winged needle used in the present invention, anyknown conventional foldable winged needle, for example, a winged needleof which wing is flexible can be adopted. Operational procedure of thewinged needle of the present invention

The needle tube of the winged needle is punctured into the body of thepatient, with a needle cover being loosely fitted to the flexible tubeof the winged needle to which the tube is connected. While the wingedneedle is being punctured into the patient, it is often the case thatthe wing is fixed to the skin of the patient with a tape or the like.When infusion of pharmaceutical liquid or blood sampling is finished,the tape is removed and then the winged needle is withdrawn from thepatient body while pressing the needle tip with sterilizing cotton. Atthis moment, the needle tube is retained in the needle coverconcurrently with the withdrawal of the winged needle, the withdrawaloperation and retaining operation into the needle cover are conducted bypulling the tube toward the base end side (opposite to the needle tip)while pressing a part of the needle cover with a finger.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram view to show the overview of a wingedneedle equipped with a needle cover of the present invention.

FIG. 2 is a perspective view to show the needle cover of the firstembodiment of the present invention.

FIG. 3 is a top view of a needle cover of the present invention.

FIG. 4 is a side view of a needle cover of the present invention.

FIG. 5 is a front view of a needle cover of the present invention viewedfrom the front end opening (large-diameter opening) side.

FIG. 6 is a schematic diagram to show the dimensions of the base endopening (large-diameter opening) of a needle cover of the presentinvention.

FIG. 7 is a schematic diagram to show the wing-shape or sizes of awinged needle of the present invention.

FIG. 8 shows the state that a needle cover is mounted in a looselyfitted state to a flexible tube which is connected to the winged needleof FIG. 7.

FIG. 9 shows the procedures to retain a winged needle of the presentinvention into a needle cover.

FIG. 10 explains the folding operation or mechanism of the wing whenretaining the wing of a winged needle.

FIG. 11 is a schematic diagram to show a needle cover which has a recess18 on the base end side of the needle cover as the holding member.

FIG. 12 is a schematic diagram to show a needle cover which has aplurality of holding projections 19 on the front end side of the topface of the needle cover.

FIG. 13 shows a needle cover comprised of an upper lid 20 and a lowerlid 25 which are connected with hinge connections.

FIG. 14 is a perspective view to show the upper lid of the needle coverof FIG. 13.

FIG. 15 shows the inner faces of the upper lid 20 and the lower lid 25of a needle cover comprised of hinged upper 20 and lower 25 lids.

BEST MODE FOR CARRYING OUT THE INVENTION

By way of more detailed explanation, the present invention will bedescribed with reference to the appended drawings and embodiments.

The winged needle shown in FIG. 1 is a winged needle 2 comprising awinged needle 2, a flexible tube 8 connected to said winged needle, anda needle cover of the present invention which is loosely fitted to saidflexible tube 8.

The needle cover 1 is formed at its front end with an opening(large-diameter opening 7) through which the winged needle 2 can bepassed with the wing 6 being folded upward, and another opening 9 whichhas a diameter slightly smaller than that of the tube and through whichthe flexible tube 8 of the winged needle can be passed.

The needle cover 1 shown in FIG. 2 constitutes wing-folding facilitatingmeans for the winged needle in which the front end opening is inclinedupwardly from the front side to the base side with respect to the baseface to form an inclined opening face. And the needle cover 1 comprises:a substantially flat bottom face 3 which allows it to be laid stably onthe skin surface of the patient; a couple of side faces 4 a, 4 bconnected to the bottom face 3; and a top face 5 connected to both sidefaces, whereby the winged needle 2 is retained in the internal spacesurrounded by those wall faces of the needle cover 1.

The needle cover 1 shown in FIG. 3 and FIG. 4 is a needle cover formedwith an inclined opening face which is inclined upwardly from the baseend to the front end with respect to the bottom face as with the oneshown in FIG. 2. The inclination angle α of the base end opening shownin FIG. 4 may be fixed or may increase toward the base end. When theangle increases toward the base end, it may be configured to increasestepwise or in a curved line. Moreover, the inclination angle α ispreferably 22.5 to 80.0 degrees. When the inclination angle is belowthat range, although it will be easy to retain the winged needle intothe needle cover, the length of the needle cover will become large.Conversely, when the inclination angle exceeds that range, it willbecome difficult to insert the needle into the cover, and the mobility(sliding ease) also degrades due to reduced effects of the wingorienting/folding.

The needle cover 2 in FIG. 5 is one which is configured such that bothside faces 4 a, 4 b bulge outwardly in the opposite direction to theinternal space as support means for modifying the shape and position ofthe wing 6 so that the wing can be readily rolled up. Though the bulgingpart in this figure has a shape with an angular apex 12 projectingoutwardly from the inside of the internal space, the apex 12 of thebulging part may have a curved shape as described above. Suchconfiguration as shown in the figure, in which both side faces bulgeoutwardly in the direction opposite to the internal space, would betterfacilitate the upward orientation and folding of the wing than aconfiguration in which both side faces 4 a, 4 b of the needle cover arevertical, making the insertion into the needle cover easier, andtherefore is preferable.

The needle cover of FIG. 5 is formed with wing-direction restrictingmeans by means of two straight ribs 14 (hereinafter, also called asguide rib) in the central part of the top face of the needle coverinternal space as support means for inserting/moving the winged needleinto the needle cover (it is the same for FIGS. 2 and 8). This guide rib14 has its one end at the front end opening, and guides the folded wingtip 11 when the winged needle 2 moves in the needle cover 1, thusrestricting the moving path of the winged needle.

Thus, since the wing tip 11 abuts against the guide rib 14, and thewinged needle 2 moves along it in the needle cover 1, the tip of theneedle 13 would not stagger while moving. It is often the case inclinical practices that the winged needle 2 is required to be retainedin the needle cover 1 as soon as it is withdrawn from the patient body.In such cases, the above described guide ribs 14 are effective. That is,when withdrawing the needle 13 from the patient's body while retainingthe needle 13 into the cover 1, the guide ribs 14 would restrict thedirection of the needle tip, thereby allowing the needle to be withdrawnin a straight fashion. Staggering of the needle tip during thewithdrawal may pose a risk of damaging the blood vessels. Therefore,with the staggering of the needle tip being prevented, the operatorwould not be distracted by the needle tip, and will be able to retractthe tube 8 a of the base end side while pressing only the needle cover.And, by retracting the flexible tube 8, the needle will be withdrawnfrom the patient body and, at the same, retained into the needle cover.

The needle cover 1 of FIG. 6 is one characterized in that the dimensionof the opening part satisfies a condition: L/3≦d1≦L, where L is thelength of the inner perimeter of the inclined opening and d1 is thedistance between both wing ends of the winged needle to be retained insaid needle cover.

The winged needle of FIG. 7 is one characterized in that the base endedges 16 of the wing are configured to have an inclination angle γ withrespect to the plane normal to the axis of the tube. Configuring suchthat the base end edges 16 of the wing of the winged needle have aninclination angle with respect to the tube axis of the winged needlemakes it easy to retain the wing of the winged needle into the needlecover.

The winged needle 2 in FIG. 8 is one configured such that a needle cover1 as shown in FIGS. 3 to 6 is loosely fitted to the flexible tube (8 a,8 b) coupled to the winged needle 2 having wings with an inclinationangle as shown in FIG. 7. The needle cover 1 of the figure is alsoformed with direction restricting means 14 as with FIG. 5 as the supportmeans for inserting/moving winged needle 2 into the needle cover 1.

FIG. 9 explains the operation of retaining the winged needle 2 into theneedle cover 1 by pulling the base end side tube 8 a of the flexibletube 8 coupled to the winged needle 2 toward the base end.

Since the winged needle 2 used in FIG. 8 and FIG. 9 has a wing having aninclination angle with respect to the normal plane to the tube axis asdescribed above, upon retaining the winged needle 2 into the needlecover 1, the base end edge 16 abuts slantingly against the perimeteredges 7 a, 7 b of the front end opening (large-diameter opening). Andthis would allow the winged needle to be moved with less force comparedwith the case of the wing with no inclination angle.

The folding effect or mechanism of the wing when retaining the wing ofthe winged needle of the present invention will be explained in FIG. 10.

That is, the winged needle is retained into the needle cover by pullingthe base end side tube 8 a toward the base end while pressing the needlecover 1. And, since the front end opening is formed with an inclinationface and therefore, upon withdrawing the winged needle 2 into the needlecover 1, the wing 6 would be pressed against the both inclined sidefaces 4 a, 4 b of the large-diameter opening 7, thereby gradually(naturally) rolling up the wing 6 along the inclined faces. In suchstate, further pulling the tube 8 a toward the base end would cause thewing 6 to be retained in the internal space of the needle cover 1 in astate that the front end 11 of the wing is turned around toward theneedle tube 13. At this moment, since the both wing ends 11 a, 11 b areretained by being folded to the needle tube 13 side, the winged needleis easier to be withdrawn toward the base end side (forward direction)and less easy to move in the reverse direction (needle tip side). Theneedle cover in FIG. 11 is characterized in that the base end opening isan inclined opening, and that a recess 18 is provided on the base endside of the needle cover as the above-described holding member. Theneedle cover in FIG. 12 is characterized in that the base end opening isan inclined opening, and that a plurality of holding projections 19 areprovided on the front end side top face.

The needle cover shown in FIG. 13 and FIG. 15 consists of a pair ofupper 20 and lower lids 25 (a pair of split-mold members) which areintegrated by hinge connections. The upper lid 20 of the needle cover isprovided with an arcuate projection (holding member) 21, a safety line22 indicating that the wing of the winged needle is to be retained onthe base end side with respect to said line, and a marker 23 indicatingthe direction of retaining the winged needle.

The needle cover shown in FIG. 13 and FIG. 15 is fabricated byintegrally molding a pair of split-mold members together with hingeconnections; however, the pair of split-mold members may be fabricatedby coupling separately fabricated split-mold members with hingeconnections.

FIG. 14 shows the upper lid of the needle cover of FIG. 13, and atapered surface is formed at the head of the bottom face member of theneedle cover of FIG. 14 and FIG. 15. Also, the inclined opening facewhich is the wing-folding facilitating means is formed with aninclination against the axial direction of the needle cover.

Since the needle cover of FIGS. 13 to 15 is configured such that twosplit-mold members connected with a hinge 24 are engaged by a snap-lockusing a slot 26 and hook 27, even complex shapes and/or structures canbe formed with ease. In FIG. 13, since a snap-lock engaging means bymeans of a slot 30 and a hook 31 is provided also on the base endportion of the needle cover, it is possible to prevent the detachment ofthe winged needle from the base end.

EMBODIMENTS OF THE INVENTION

The needle cover 1 of the present embodiment, as shown in FIGS. 1 to 6,has the base end opening of which opening part has a polygonal(octagonal) shape. The needle cover has a width (maximum diameterpoint)xof 22 mm, an axial length (longest part) y of 70 mm, a height(highest point) z of 12 mm. The inner perimeter L of the internal spaceof the needle cover is 65.7 mm, the length d1 of the wing 6 is 34 mm,wing area S is 300 to 400 mm².

The width of the bottom face is 18.3 mm and formed to be nearly flat.The bulging part 12 is formed at a height of about 3 to 4 mm from thebottom face, and the apex angle β is about 131 degrees. The bulging part12 is provided on both side faces 4 a, 4 b, and its end portion startsfrom the large-diameter opening 7 to an extent of 55.0 mm in the axialdirection.

The large-diameter opening 7 on the front end side is configured to havean inclination angle α of 45 degrees, the area of the opening beingabout 330 mm². The small-diameter opening 9 has an outer diameter of 4×5(irregular circle) mm which is slightly smaller than the outer diameterof the tube 8 of 5.5 mm. The top face 5 of the needle cover is providedon its outer surface with a plurality of arcuate projections 21 having aheight of 2 to 3 mm and a width of 0.2 mm as the holding means. Twostripe ribs 14 are formed in the central part of the internal space ofthe top face 5 as the direction restricting means. The two stripe ribs14 placed about 1.5 mm apart and parallel in the axial direction, areformed starting from the large-diameter opening 7 and extending over35.0 mm in the axial direction. The height of the ribs is about 1.8 mm.

The wing 6 of the winged needle is configured such that the base endedge 16 are inclined by 3 degrees with respect to the plane normal tothe tube axis, and the inclination angle γ of this base end opening ischanged to facilitate the retaining operation. The length of the needletube protruding from the needle base is 22 mm, axial length of theneedle base where the wing is formed is about 10 mm.

The needle cover is made of polypropylene, and the portion of itsinternal space which contact with the wing is finished by an embossprocess. Also, the wing of the needle is made of vinyl chloride resinhaving a hardness of 70 as specified by JIS-A. The thickness of the wingis about 1.0 mm, and its material is soft and easily formed.

1. A needle cover having a front end opening through which a winged needle as a whole is retracted and a base end opening through which a flexible tube connected to said winged needle is passable , the needle cover being capable of retaining the winged needle as a whole with a needle tube of the winged needle being prevented from re-protruding, characterized in that the needle cover comprises wing-folding facilitating means which is formed in said front end opening and cam fold the wings of the winged needle by gradually turning end portions of the wings upward and toward each other when the winged needle as a whole is retracted into said needle cover through said front end opening, wherein said needle cover comprises a substantially flat bottom face, both side faces connected to said bottom face part, and a top face connected to said both side faces.
 2. The needle cover according to claim 1, characterized in that the wing-folding facilitating means is configured to be an inclined opening face in which the front end opening is inclined upward from the front end side toward the base end side with respect to the bottom face of said needle cover.
 3. The needle cover according to claim 2, characterized in that the dimension of the needle cover satisfies a condition: L/3

d1 □L, where L is the length of the inner perimeter of the inclined opening, and d1 is the distance between both wing ends of the winged needle to be retained in the needle cover.
 4. The needle cover according to claim 1, characterized by comprising wing-retention support means.
 5. The needle cover according to claim 4, characterized in that the wing-retention support means is configured such that at least the side faces and/or the top face of the front end opening have a convex apex protruding in the outward direction which is the opposite direction to the inside of the internal space of the needle cover, and said convex apex is formed through the entire region of both side faces of the needle cover in the axial direction, or over the region from said both end opening to the portion of both side faces against which the wing abuts when the needle is completely covered with the needle cover.
 6. The needle cover according to claim 5, characterized in that said convex apex has an angle ranging from 110 to 170 degrees.
 7. The needle cover according to claim 1, characterized by comprising wing slide-resistance reducing means and/or wing-direction restricting means.
 8. The needle cover according to claim 1, characterized by comprising a holding (pressing) member.
 9. The needle cover according to claim 1, characterized in that the hole diameter of the base end opening is equal to or slightly smaller than the diameter of the flexible tube coupled to the winged needle.
 10. The needle cover according to claim 1, characterized in that the front end opening has a large-diameter in which L is 4 to 8 cm.
 11. The needle cover according to claim 1, characterized by consisting of a pair of split-mold members which can be engaged wit a binge.
 12. The needle cover according to claim 11, characterized in that both of the hinge twining parts used to form said binge and the engaging free for engaging the pair of split-mold members are formed along a convex apex of said wing-retention support means.
 13. A winged needle with a wing-retraction type inadvertent puncture protector comprising: a winged needle, a flexible tube connected to said winged needle, and a needle cover having a front end opening trough which a winged needle as a whole is retracted and a base end opening through which a flexible tube connected to said winged needle is passable, the needle cover being capable of retaining the winged needle as a whole with a needle tube of the winged needle being prevented from re-protruding, characterized in that the needle cover comprises wing-folding facilitating means which is formed in said front end opening and can fold the wings of the winged needle by gradually turning end portions of the wings upward and toward each other when the winged needle as a whole is retracted into said needle cover through said front end opening, wherein said base end side edges of both wings of the winged needle are configured to have an inclination angle against a plane normal to the tube axis; wherein said needle cover is loosely fitted to said flexible tube.
 14. The winged needle with a wing-retraction type inadvertent puncture protector according to claim 13, characterized in that the hardness of the wing of the winged needle is within the range of 10 to 100 as specified by JIS-A.
 15. The winged needle with a wing-retraction type inadvertent puncture protector according to claim 13, characterized in that both wings of the winged needle have a structure that can be turned upward with ease by means of the wing-folding facilitating means of the needle cover.
 16. The winged needle with a wing-retraction type inadvertent puncture protector according to claim 13, characterized in that said inclination angle is within the range of 22.5 to 80.0 degrees. 